This invention relates generally to boiler-furnaces of the tubular panel type having superheaters suspended across the upper portion thereof. Access to a superheater suspended across the upper portion of a large furnace is both difficult and dangerous because of its inaccessability and because of the great height of the furnace involved. Frequently, access platforms are suspended from cables that are anchored in the roof of the furnace, however such platforms are unsteady and thereby provide an insecure support for workmen that may be suspended approximately 100 feet above the furnace floor. Moreover, furnaces must be shut down for a long period of time to permit cooling before workmen may freely enter the furnace to build the scaffolding necessary so repairs may be slow and expensive.
Accordingly, the down time of furnaces being repaired, the costs of repair, and the danger associated therewith together constitute problems that rank high in the cause of furnace maintenance.